This symposium will cover the chemistry of nucleosides, nucleotides, and analogs. This includes synthesis as well as chemical and physical methods used to elucidate the structures of these compounds. The biological activity of nucleosides, nucleotides and analogs will also be discussed. Included in these discussions will be the methods used to test these compounds for their carcinostatic, antiviral, or antibacterial activity, as well as their possible mechanism of action.